Part L1B Building Regulations Compliance for Conversions


If you're converting a building or changing its use, you'll need to demonstrate compliance with Part L1B of the Building regulations.  This means getting a SAP calculation for the development to show its likely energy performance.


Demonstrating to Building Control that your extension meets the requirements can be challenging if you are not familiar with the Building Regulations, Construction U-Value calculations, and the full SAP Assessment procedure. But UK Energy Assessors can help, whatever stage of build you are at!  SAP calculations are done based on existing and proposed plans and the detailed specification for construction and building services.  This means we can do the calculations from our offices and there is normally no need for site visits or surveys.


For a conversion, SAP assessment normally take place over two stages:

  • Design Stage - before work starts to make sure that the design will achieve a compliant build.  Building control will often insist on a design stage SAP assessment being done before construction commences.
  • As-built stage - to achieve sign off for the development from building control and to provide the EPC for any newly created dwellings.


How do I get a SAP calculation for my conversion?

You'll need to appoint a qualified On Construction Domestic Energy Assessor - commonly known as a SAP assessor.  Conversion projects can be tricky so detailed architectural design experience can be a real benefit.  At UK Energy Assessors, our SAP team are not only qualified in Energy Assessment and SAP, but we are also qualified architectural technologists.  We can provide a fixed price quotation and can normally turn around assessments within 48 hours of information being provided.  We can liaise with architects, builders, planning officers and building control and guide you through the process of achieving compliance.  Fill in the form opposite to get our quotation and let UK Energy Assessors take care of you conversion project.


When Should we Start the SAP Assessment Process?

As soon as possible! It is always easier to change your design than it is to have to construct an argument for compliance based on the as-built conversion. UK Energy Assessors are qualified Architecture Technologists and Energy Assessors and we pride ourselves on helping our clients to achieve compliance for their homes, whatever stage the build is at.